Skip to main content
Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 3, Problem 28

Graph each piecewise-defined function.
f(x)={2xif x<33x1if 3x24xif x>2f(x) =\(\begin{cases}\)-2x & \(\text{if }\) x < -3 \\3x - 1 & \(\text{if }\) -3 \(\leq\) x \(\leq\) 2 \\-4x & \(\text{if }\) x > 2\(\end{cases}\)

Verified step by step guidance
1
Identify the three pieces of the piecewise function and their corresponding domains: \(f(x) = \begin{cases} 3x + 7, & \text{if } x < -4 \\ -2x + 2, & \text{if } -4 \leq x \leq 3 \\ 5x - 10, & \text{if } x > 3 \end{cases}\)
For the first piece, \(f(x) = 3x + 7\) when \(x < -4\), plot the line \(y = 3x + 7\) only for values of \(x\) less than \(-4\). Use an open circle at \(x = -4\) to indicate that this point is not included in this piece.
For the second piece, \(f(x) = -2x + 2\) when \(-4 \leq x \leq 3\), plot the line \(y = -2x + 2\) for \(x\) values from \(-4\) to \(3\) inclusive. Use closed circles at \(x = -4\) and \(x = 3\) to show these points are included.
For the third piece, \(f(x) = 5x - 10\) when \(x > 3\), plot the line \(y = 5x - 10\) for \(x\) values greater than \(3\). Use an open circle at \(x = 3\) to indicate this point is not included in this piece.
Combine all three pieces on the same coordinate plane, making sure to respect the domain restrictions and endpoint types (open or closed circles) to accurately represent the piecewise function.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
7m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Piecewise-Defined Functions

A piecewise-defined function is a function composed of multiple sub-functions, each applying to a specific interval of the domain. Understanding how to interpret and graph each piece separately is essential for analyzing the overall function.
Recommended video:
3:51
Domain Restrictions of Composed Functions

Graphing Linear Functions

Each piece of the piecewise function is a linear function of the form y = mx + b. Knowing how to graph linear functions by identifying slope and y-intercept helps in plotting each segment accurately on the coordinate plane.
Recommended video:
5:26
Graphs of Logarithmic Functions

Domain Restrictions and Continuity

Each sub-function applies only within a specified domain interval. Recognizing these domain restrictions ensures correct graphing boundaries and helps determine if the function is continuous or has breaks at the interval endpoints.
Recommended video:
3:51
Domain Restrictions of Composed Functions